My group has been toying with the idea of adding some new items lately, namely Tome of Magic-esque Skill Manuals. The basic idea is that there would be like a "manual of speed" which a character could use to auto-learn one speed skill, it would cost something similar to a ToM, maybe a bit less so that they might see some use ever, and that a character could use only one manual for each skill set they have, if you can find them.
I think this idea was born out of two things: 1) stuff like that existing in a lot RPG video games, like Skyrim and WoW, and 2) we've had a super long campaign going on for a while, several characters have completely maxed out their experience, and its getting boring but we don't want to stop.
Any thoughts on this sort of thing?